The present invention relates in a general way to couplers.
As is well known, a coupler is a mechanical assembly comprising clamping modules, intended in particular for applying a preclamping force so as to provide mechanical linkage and fluid-tightness between an articulated product loading and unloading arms, in particular for fluid products, for example petroleum products (liquefied natural gas etc.), and a complementary means installed on a ship.
The present invention relates more particularly to the case when the coupler is a hydraulic coupler with several clamping modules, in practice three or more, capable of conveying liquid products at very low temperatures (down to −196° C.).
According to a known arrangement, each clamping module comprises a clamping jaw designed for connecting the coupler to a complementary means, such as a manifold, and an actuating system proper to the said jaw and comprising a device of the screw/nut type driven by a motor. The jaw is carried by a system of rods articulated at one of its ends, on a support, the actuating system acting upon the system of rods in order to impel the jaw towards a clamping position or to bring it back to a resting position.
However, in devices of this type that are already known, the forces transmitted by the rods depend on the thickness of the manifold flange at the clamping location which, in practice, varies from one location to another on the flange.
As a result the clamping is often insufficient or excessive.